An internal gear pump is known from the patent DE 196 13 833 B4. It comprises two gear wheels, namely a ring gear, which may also be referred to as an internally toothed wheel, and an externally toothed wheel which for the sake of a clear distinction will be referred to hereinafter as a pinion. The ring gear and the pinion are together referred to as gear wheels. The pinion is arranged eccentrically in the ring gear, so that the two gear wheels mesh with one another in a circumferential section. The two gear wheels delimit between them a crescent-shaped pump chamber which extends in the circumferential direction from a suction region to a pressure region of the internal gear pump. The pump chamber extends outside the circumferential section in which the two gears mesh with one another. The pump chamber of such an internal gear pump is sometimes referred to as a displacement chamber or simply as an intermediate or free space. The ring gear delimits the pump chamber on the outside while the pinion delimits it on the inside. The suction region may also be understood as the inlet and the pressure region as the outlet of the internal gear pump.
In order to delimit the pump chamber laterally, the known internal gear pump has on each front face of the two gear wheels a so-called axial disk which bears against the front faces of the gear wheels with its inner side oriented towards the gear wheels and is subjected to pressure on its outer side oriented away from the gear wheels. The inner side and the outer side of the axial disk are its front faces (!). The axial disks are intended to seal against the gear wheels of the internal gear pump and the stationary axial disks are intended to have low friction with respect to the rotating gear wheels. The axial disks do not seal hermetically; leakage occurs between the axial disks and the gear wheels. The aim is to find a good compromise between a good sealing effect on the one hand and low friction on the other between the axial disks and the gear wheels in each case.